sweetie vs dearest

sweetie and dearest both are nouns.

Word	Noun	Adjective	Verb	Adverb
sweetie	Yes	No	No	No
dearest	Yes	No	No	No

As nouns, sweetie and dearest are synonyms defined as:

Other synonyms of sweetie include baby, beloved, darling, dear, dearie, deary, honey, love, sweetheart.

sweetie (noun)	dearest (noun)
a person loved by another person	a beloved person; used as terms of endearment
a beloved person; used as terms of endearment